This invention relates to body supports and teaching aids, particularly, but not necessarily exclusively for use during skiing.
Skiing is a sport enjoyed by considerable numbers of skiers over a wide age group. Even relatively gentle skiing down ski runs that are not severe and better suited to less experienced skiers imposes considerable strains on the muscles of the skier, particularly in the legs, resulting from the skier adopting an incorrect stance or posture along with the repeated impacts of the skis with uneven compacted snow or ice causing a bouncing effect that the skier must combat by repeatedly bending the legs, whilst at the same time the legs must continue to support the skier. The more severe is a ski slope, the greater is the stress on the legs, and consequently all skiers, whether young and with leg muscles not yet fully developed, in their prime and wanting to ski for prolonged periods in difficult conditions, or more elderly and with leg muscles past their prime, can benefit from the use of body weight supports that assist in setting the skier in a correct position.
Body weight supports and teaching aids must not only allow a part of the body weight of the skier to be removed from the skier""s legs, but also must allow the legs to bend at the knee, and additionally must not inhibit a skier from moving the hips laterally to incline the legs to set the skis on edge and allow the skier to implement turning movements to the left and to the right.
There have been earlier proposals for providing leg supports, where skiers employ poles connected to the skiers boots and linked by springs at the upper ends of the poles to a harness worn by the skier. Not only is such a construction cumbersome, springs of conventional construction have a variable load resistance as they are stretched or compressed, and consequently give a variable supporting force that is not conducive to good skiing. Additional to this, prior art constructions do not give any effective assistance in putting a skier into a correct skiing posture. Such a construction has the further disadvantage in stopping the skier from bending and flexing the legs when not skiing and consequently a skier cannot board such as ski lifts or chairs with the support mean fitted for use. Consequently the construction must be dismantled to allow a skier to sit and walk normally, and reassembled at the top of a ski slope. The construction involved is inevitably visible, and aesthetically unattractive. Whilst giving support to the skier, such constructions offer nothing by way of assistance in setting the skier in a correct position or posture.
The object of the invention is to provide a body weight support and teaching aid, particularly for use in skiing, that is effective and avoids those disadvantages mentioned above and provides still further advantages.
According to the present invention a body weight support configured for connection to a boot of a user is characterised in that said body weight support has a first upper member adapted for location against the thigh area of the leg, a second lower member adapted for location against the calf area of the leg, a pivotal connection between the first and second members, the second member being connectable to the boot of the user to form a connection between the second member and the boot, load bearing means formed by at least one compression spring located on the support to provide a resistance to pivotal movement between the first and second members, and deactivating means configured to provide that said load bearing means is deactivatable to permit substantially free pivotal movement between the first and second members, wherein said deactivating means is actuateable to provide that the load bearing means is inactive through a full range of motion and remains inactive while the user walks and sits.
Preferably, the connection between the second member and the boot is a rod fitted to a socket at the lower end of the second member and the socket and the rod may be correspondingly threaded, the rod extending to a snap fit connection on the boot, preferably at the rear of the boot.
With the majority of able bodied skiers, it is desirable to provide two supports, one for each leg, with the upper ends of the supports connected by a strap or other member extending around and below the posterior of the skier.
With a disabled skier, such as those with one leg only, two support members can be provided to locate to either side of the one leg, and a strap or other member extending around the back of the thigh and connecting the upper ends of the two supports.
The upper member may be formed as a generally straight elongate, eg rectangular bar, to locate on the outside of the respective leg of the user, and is provided with a bracket at its upper end for straps to engage around the upper leg or thigh area, in addition to a strap to pass around the posterior of the user. The lower member extends from the pivot with an upper member to a curved and plate-like lower part to locate behind the calf muscle of the respective leg of the user, and a lower fixing strap may be attached to the lower end of the lower support. Desirably, quick release fittings are provided on all of the straps. A quick release fitting may be located on a shin support or protector, attached to the lower member and adapted to overlie the shin of the user.
In one possible form of construction, a load bearing means is attached to the outer surface of the upper support. The load bearing means may be such that when active it provides a substantially constant force, such as can be provided by a gas strut. Thus, the gas strut may be located in a cradle on the upper leg support, there being a cable connecting the gas strut to the lower leg support, said cable passing around a guide at the pivotal connection between the upper and lower members. The cylinder of the gas strut may be attached to a cradle secured to the upper member, below which is a cable attachment member. The cable attachment member has two guide rods extending through corresponding holes in the cradle which extend to a bridging member connected to and extending across the tops of the guide rods. Desirably, in the bridging member is a rotatable stop, able to be rotated from a position where it forms an abutment to engage the top of a piston rod extending from the cylinder, to a position where a through hole in the stop is aligned with the piston rod, to allow the passage of the piston rod therethrough. With the rotatable stop in a position where its hole is aligned with the piston rod of the gas strut, the bridging member could slide down the guide rods, and with the piston rod engaging the hole, the rotatable member could not be rotated to activate the support means. Therefore, between the cradle and the bridging member, the guide rods may have surrounding coil return springs to hold the bridging member in an elevated position with the rotatable member clear of the top of the piston rod. An alternate possibility is to have a coil spring surrounding the or each gas strut, and bearing against the cradle and the bridging member.
In the alternative, load bearing means may be a compression spring of required strength, located on the cradle in place of the gas strut. The coil spring may surround a sleeve slidably mounted on a locating rod extending from the cradle, and the coil spring may be positioned between an abutment on the sleeve and the bottom of the cradle. The compression spring is such that it has a strength to allow a proportion of the body weight of the user to be supported before the spring is fully compressed, and compression strength can be selected to suit the body weight of the user. Above the abutment there may be an operating rod able to co-operate with the bridging member, to engage it when it is rotated to a position to serve as an abutment, and pass through a through hole when the bridging member is rotated to bring the through hole into alignment with the operating rod. In common with the embodiment employing a gas strut, two guide rods may extend from a cable attachment member located below the cradle, through holes in the cradle and to the bridging member to which they are connected. Again, coil springs may surround the guide rods to hold the bridging member in an elevated position.
When the support means is activated, the user is immediately faced with the full force of the or each gas strut or the coil spring as he or she first settles into a skiing position. It is therefore preferred to have the or each gas strut slidably mounted in the cradle, and for a coil spring to be provided below the or each gas strut. As a result, there is a cushion effect provided by the compressing of the coil spring below the gas strut, and when the spring is compressed, the gas struts then come into play. With a coil spring, it may be a primary coil spring extending between the abutment on the sleeve and a slider on the sleeve, below which is a secondary coil spring of a lesser rating. Here, there is a cushion effect provided by the secondary coil spring, and when the secondary spring is compressed the primary coil spring then comes into play.
Whilst the presence of coil springs surrounding the guide rods and positioned below the gas struts or primary coil springs can provide a useful supplement to the load bearing characteristics of the or each gas strut or the primary spring, they should be of a rating such that with the load bearing means deactivated, they do not provide a major resistance to the freedom of the upper and lower members to pivot, and hence allow the skier to walk and sit relatively normally without the need to remove the body support means.
Simple and unobtrusive lever means may be provided to rotate the stop means.
Thus, with two body weight support means attached to the outside of each leg and interconnected by the strap at their upper ends, with, if the skier requires it, suitable padding between the legs and the supports, the skiers overtrousers can be put on, totalling hiding the support from view, and yet easily activated by the movement of the lever on the rotatable stop through the overtrousers. The means of the invention can be fitted in the privacy of the skiers room, leaving the skier with nothing more to do when putting on ski boots but to snap fit the bottom of the rod to the fitting on the boot.
When fitted but not activated, the skier has substantially full leg mobility, allowing normal walking and sitting, and when required to be activated such as at the top of a ski slope, simple movement of the lever puts the body support means in an active state. Thus, as the legs of the skier bend at the knees, and the body of the skier descends, pivoting of the upper and lower members causes a downward force on the cable that is resisted by the gas strut or primary spring as the bridging member is drawn downwards attempting to push the piston into the cylinder or compress the primary spring, as a consequence of which, a proportion of the body weight of the skier is transferred through the posterior strap, the support mechanism and the rod attached to the lower member to the boot of the skier.
To provide a skier with a means of increasing or decreasing the degree of support provided, two or more gas struts or primary springs may be provided, one, both or all of which can be selectively rendered active, to give a skier the ability to employ one, or more gas struts or primary springs.
In addition to selective activation and deactivation, it is a most important facet of the invention, that when a skier is not actually skiing, but intends to ski, removal of the support means is avoided.
It will readily be understood that the support exemplified above can be reversed in the sense of placing the load bearing means on the lower support member and running the cable around the cable guide to a fixing point on the upper support member.
In both circumstances, the fixing point for the cable is preferably provided with an adjuster to take any slack out of the cable and ensure that the load bearing means is activated when the skier effects a downward or sitting action. In addition to giving body weight support the instant a skier assumes the position for skiing, correct setting of the cable, governing when a further downward movement of the body is attempted, has the considerable advantage of causing the skier to assume a technically correct posture for skiing. More than this and during skiing itself, the constant force resisting body downward movement acts as a most effective cushion or shock absorber to help the prevention of wear and damage particularly to the knees of the skier.
With the load bearing means deactivated, the skier can walk and sit with relative ease, and when ready to ski, by a simple rotation of the stop means, can easily and fully activate the load bearing means, to give considerable support to the body weight of the skier by its transfer to the skier""s boot, and hence eliminate a substantial proportion of the strain otherwise imposed on the muscles of the skier""s legs, whilst at the same time maintaining substantial leg and knee mobility, necessary to enable a skier to ski correctly.